1. Field of the Invention
The present application relates in general to the field of aerodynamic structures for rotorcraft; but more particularly, horizontal stabilizers for rotorcraft.
2. Description of Related Art
There are many different types of rotorcraft, including helicopters, tandem rotor helicopters, tiltrotor aircraft, four-rotor tiltrotor aircraft, tilt wing aircraft, and tail sitter aircraft. At least some of these aforementioned rotorcraft utilize horizontal stabilizers attached to a tailboom in order to provide aerodynamic stability during flight. Typically, a horizontal stabilizer will have one or more horizontal surfaces to aid in aerodynamic pitch stability. Additionally, a horizontal stabilizer may have one or more vertical surfaces to aid in aerodynamic yaw stability. It is often important for a rotorcraft to have the capability of reducing its overall volume for stowage reasons. For example, when transporting multiple rotorcraft in a cargo portion of a cargo plane, it is advantageous to convert the rotorcraft into a stowage configuration. In addition, it is also advantageous to be able to rapidly convert rotorcraft from a stowed configuration to an operable configuration, i.e. rapid deployment.
Referring to FIG. 1, a rotorcraft 101 is depicted with a conventional horizontal stabilizer 103 attached to a tailboom 109. A forward end of tailboom 109 is attached to fuselage 119. A tail rotor 121 is carried by an aft end of tailboom 109.
Referring now to FIG. 2, conventional horizontal stabilizer 103 of rotorcraft 101 is shown in further detail. Horizontal structure 113 extends through an opening in tailboom 109 and is permanently attached to skin 111 of tailboom 109 with fasteners 107. Endplates 115a and 115b are attached to horizontal structure 113 with a plurality of endplate fasteners 117a and 117b. Folding mechanisms 105a and 105b provide a method of stowage for horizontal structure 113. For horizontal stabilizer 103 to be in a stowable configuration, endplates 115a and 115b must be detached by removing fasteners 117a and 117b. Then, because horizontal structure 113 is permanently attached to tailboom 109, folding mechanism 105a and 105b must be used to allow the outboard portions of structure 113 to fold upward to a stowed position.
It is often desirable to create more efficient rotorcraft structure, thereby reducing the number of fasteners, reducing weight, and decreasing the amount of time it takes to stow and deploy an aircraft. There are many rotorcraft horizontal stabilizers known in the art; however, considerable room for improvement remains.
While the system of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the system to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present application as defined by the appended claims.